Are Mormons advised not to drink carbonated beverages?

Yes, if they want to. The Church of Jesus Christ of Latter-day Saints (the 'Mormon' church) does not prohibit consumption of soda drinks.

Mormons do follow a health code which prohibits 'strong drinks' (alcohol) and 'hot drinks' (coffee and tea) as well as tobacco and illegal drugs. Some Mormons do choose to avoid caffeinated sodas, and a few even avoid soda drinks altogether, but this is purely a personal choice based on the fact that they are unhealthy, it is not a requirement of their church. Many Mormons are focused on staying healthy, as they believe their bodies are sacred gifts from God and should be cared for.

You can check out the "Related Links" below to learn more about Mormons and their health code.